Disposable absorbent articles are well know from the art for receiving and retaining bodily discharges, such as urine, menstrual fluids, or faecal materials. Thereby, two basic mechanisms are relied on. First, the containment of such discharges is generally achieved by a gasketing functionality, such as through impermeable materials or construction of sealings between the article and—in most cases—the skin of the wearer. The other key mechanism is to retain the discharges within the absorbent article, generally achieved by using an absorbent structure to pick up the discharges. In most cases, the absorption mechanism is directed towards handling of the aqueous components of the discharges.
One of the key performance criteria against which a absorbent article has to deliver is the acquisition speed. Obviously, a fast liquid acquisition warrants a short time span between exudation and storage of the exudate.
However, elements absorbent articles are often made from polymeric materials such as polyolefins which are hydrophobic by nature. For example, these elements may be made from thermo-bonded nonwoven materials. These materials are chosen since they offer advantages for example in their broad availability, ease of manufacture, cost, and the like.
It is well known in the prior art to hydrophilize such elements by adding a hydrophilizing agent to at least the surface of such elements. During acquisition of an aqueous liquid, surfactant is released into the acquired liquid, the surface tension reduction of the liquid is reduced and therefore the surfaces of the elements may be wetted by the liquid.
Further, it is taught to apply the hydrophilizing agent in high concentrations in order to maintain the hydrophilicity of the liquid handling structure after subsequent liquid insults in order to not compromise the liquid handling performance of the liquid handling structure.
However, by releasing the surfactant into the acquired liquid the surface tension of the liquid is substantially reduced. Thus, the capillary suction of the absorbent article and hence the acquisition speed is also reduced.
It has been another recent trend in the absorbent article field to provide liquid handling structures with large open pores to readily accept high viscosity liquids such as faeces. Of course, such large open pores also reduce the capillary suction and the liquid acquisition speed of the absorbent article. Therefore, the negative impact of the surface tension reduction of the acquired liquid is particularly pronounced in absorbent articles which comprise such open structures.
Therefore, it is an object of the present invention to provide an absorbent article which overcomes the problems posed by the prior art absorbent articles.
It is a particular object of the present invention to provide an absorbent article which does not substantially impact the surface tension of the acquired liquid.
It is a further subject of the present invention to provide an absorbent article which allows to combine good liquid acquisition performance with a liquid handling structure having large open pores under an apertured hydrophobic topsheet.
It is a further object of the present invention provide absorbent article which comprises components only releasing small amounts of surfactant into the acquired liquid.
It is further object present invention to provide absorbent article which has a good liquid acquisition speed and a low rewet through the topsheet.